1. [n]  mounting consisting of a border or background for a picture
2. [n]  floor covering of coarse fabric (usually of straw or hemp)

MATTING is a 7 letter word that starts with M.

1. \Mat"ting\, n. [From {Mat}, v. t. & i.]
   1. The act of interweaving or tangling together so as to make
      a mat; the process of becoming matted.
   
   2. Mats, in general, or collectively; mat work; a matlike
      fabric, for use in covering floors, packing articles, and
      the like; a kind of carpeting made of straw, etc.
   
   3. Materials for mats.
   
   4. An ornamental border. See 3d {Mat}, 4.
   
   

2. \Mat"ting\, n. [See {Matte}.]
   A dull, lusterless surface in certain of the arts, as
   gilding, metal work, glassmaking, etc.